Catalyst and method for production of methylamines

Abstract

This invention relates to an improved catalyst and method for the selective production of methylamines. More particularly, it is concerned with the preparation of stable highly active catalysts for producing methylamines by a catalytic reaction of ammonia or substituted amines and binary synthesis gas (CO+H2).

What is claimed is: 
     
       1. An alkali-containing copper/zinc oxide catalyst useful for the production of methanol consisting essentially of a binary system comprising a mixture of copper metal and zinc oxide prepared by: (a) dissolving soluble salts of copper and zinc in an aqueous solution;   (b) coprecipitating the metal hydroxycarbonates and/or metal hydroxynitrates thereof by addition of a sufficient concentration of an aqueous basic carbonate;   (c) separating the precipitate, drying, and calcining same to form the equivalent metal oxides;   (d) reducing the calcined metal oxides in a hydrogen atmosphere substantially to convert copper oxide to lower valence states of copper;   (e) treating the resulting mixture in an oxygen-free atmosphere with a dilute, aqueous solution of an alkali metal hydroxide or an alkali metal salt; and   (f) evaporating the moisture in an oxygen-free environment to recover a dried alkali/copper/zinc oxide catalytic material.   
     
     
       2. The catalyst of claim 1, wherein copper nitrate and zinc nitrate are the salts used in step (a). 
     
     
       3. The catalyst of claim 1 wherein the alkali metal introduced is cesium. 
     
     
       4. The catalyst of claim 1, wherein the alkali metal introduced is rubidium. 
     
     
       5. The catalyst of claim 1, wherein the alkali metal introduced is potassium. 
     
     
       6. The catalyst of claim 1, wherein said catalyst includes from 2 to 70 mol% copper and from 30 to 98 mol% zinc oxide. 
     
     
       7. The catalyst of claim 1, wherein said catalyst includes from 0.01 to 1.0 mol% of alkali deposited in and on the surfaces of said catalyst. 
     
     
       8. The catalyst of claim 1, wherein step (e) is carried out with a mixture of alkali metal hydroxides or salts consisting of one or more from the group of cesium, rubidium, and potassium, and one or more from the group of lithium, sodium, potassium, rubidium, and cesium. 
     
     
       9. A method of producing methylamines from binary synthesis gas and ammonia at conditions of 150°-300° C., 14.7-1500 psig and GHSV of 500-20,000 liters of feed gas/liter of catalyst/hour using the catalysts of claim 1 or claim 2 or claim 3 or claim 4 or claim 5 or claim 6 or claim 7 or claim 8. 
     
     
       10. A method of producing methylamines from binary synthesis gas and amines at conditions of 150°-300° C., 14.7-1500 psig and GHSV of 500-20,000 liters of feed gas/liter of catalyst/hour using substituted amines of the general formula NH 2  R using the catalysts of claim 1 or claim 2 or claim 3 or claim 4 or claim 5 or claim 6 or claim 7 or claim 8.